In the summer of 2002, Kelly Flatley and Brendan Synnott joined forces to launch a homemade granola business out of Flatley's parents' home. They had no advertising budget, so they had to find other ways to let consumers know about Bear Naked Granola. The entrepreneurs went door-to-door to small specialty and natural food stores. They also set up tables and tents at community events and 5K charity runs where they gave away samples of their granola. From this information, you can infer that Flatley and Synnott used the method for promoting their product.

David consumes two things: gasoline (g) and bread (b). david's utility function is u(g, b) = 10g^0.25 b^0.75. use the lagrange technique to solve for david's optimal choices of gasoline and bread as a function of the price of gasoline, p_g, the price of bread, p_b, and his income m. with recent decrease in the price of gasoline (maybe due to external shock such as shale gas production) does david increase his consumption of gasoline? for david, how does partial differential g/partial differential p_g depend on his income m? that is, how does david's change in gasoline consumption due to an increase in the price of gasoline depend on his income level? to answer these questions, find the cross-partial derivative, |partial differential^2 g/partial differential m partial differential p_g.